1. Field of Invention
The present invention relates to a method for manufacturing a sputtering target. More particularly, the present invention relates to method for manufacturing a metal ceramic composite sputtering target.
2. Description of Related Art
Due to continuous breakthroughs of the development and research on the process technology and related material of hard disk, the hard disk recently developed can be used for storing a tremendous amount of data. In general, data are stored on a thin-film magnetic recording layer, and the material forming the thin-film magnetic recording layer mainly is a cobalt (Co) alloy material containing precious metals (such as platinum (Pt)), for example, CoCrPt—SiO2.
Using the preparation of a CoCrPt—SiO2 sputtering target as an example for explanation, since its material contains SiO2 ceramic, a powder metallurgy process has to be adopted for preparing the sputtering target. In brief, after a dry powder mixing process or wet powder mixing is used to fully mix a cobalt (Co) metal powder, a Chromium (Cr) metal powder and a SiO2 powder, a molding and densification process is performed onto the mixed powders to form a CoCrPt—SiO2 sputtering target. However, no matter which power mixing process is used, it is difficult to overcome the problem of failing to uniformly mixing the metal powers and the ceramic powder due to large specific weight differences between the metal powders and the ceramic powder.
In order to resolve the aforementioned problem, a conventional process ever presented a solution. Briefly speaking, in the conventional process, a Pt metal powder and a SiO2 powder having a larger particle diameter are first processed by dry ball milling and then are calcined to form a Pt—SiO2 powder. After a Co metal powder, a Cr metal powder and the Pt—SiO2 powder undergo a dry powder mixing process, a molding and densification process is performed onto the powders thus mixed to form a CoCrPt—SiO2 sputtering target. However, the CoCrPt—SiO2 sputtering target formed by the conventional process has the disadvantage of coarse SiO2 particles and still un-uniform distribution of metal and ceramic particles. When the sputtering target is applied on a subsequent thin-film sputtering process, after the sputtering target is ion bombarded by argon ions (Ar+), the coarse ceramic phase of the sputtering target will cause heterogeneous particle defects occurring on the film sputtered.
In view of the foregoing, there is a need to provide a method for manufacturing a Co alloy-based ceramic composite sputtering target, thereby overcoming the problem of failing to uniformly mixing the metal powers and the ceramic powder due to large specific weight differences between the metal powders and the ceramic powder.